cmd/godoc: some _ should be shown #7815
Description
Here is a nice trick to write an enum-like type's constant values:
g% cat x.go
package p
type T int
const (
_ T = iota
T1
T2
T3
T4
)
g%
This has two properties I wanted: (1) the values start at 1, so the zero value is not a
defined value, and (2) all the defined values have the same form on the line, so that I
can pipe them through 'sort' without breaking anything. Compare to
const (
X T = 1 + iota
Y
Z
)
Anyway, this _ trick works well for me.
It works less well for godoc:
g% godoc .
PACKAGE DOCUMENTATION
package p
import "."
CONSTANTS
const (
T1
T2
T3
T4
)
TYPES
type T int
g%
It's a bit confusing that you can't see the _ in the godoc output, since the _ is what
defines the type and value of the constants.
Worse, the constants are not attached to the type T like they normally would be:
g% godoc . T
type T int
g%
If I rename the _ to Dummy, then it works:
g% godoc . T
type T int
const (
Dummy T = iota
T1
T2
T3
T4
)
g%
What's happening here is that _ is treated as unexported and so it filters away.
(Renaming to dummy shows the same behavior as _.)
Perhaps the best fix would be to treat _ as exported for the purposes of godoc filtering
in const lists and possibly also struct fields (where _ is often padding).
I thought about saying that _ should be treated as exported for all filtering, but you
probably don't want to show things like
func _() { ... }
var _ Interface = (*Type)(nil)